Dilator apparatus

ABSTRACT

A cystotomy apparatus includes a sound from which an advancement device having a cutting tip creates a surgical pathway from the bladder through abdominal tissue to the external abdomen along a predetermined path. The cutting tip is captured and removed from the advancement device in a capture cup located in the predetermined path by an alignment structure. The cutting tip is removed from the advancement device while within the capture cup, to allow a dilator, cannula or catheter to be drawn through the surgical pathway into the bladder.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a division of U.S. application Ser. No. 12/790,313, filed May28, 2010, now U.S. Pat. No. 8,382,785. U.S. application Ser. No.12/790,313 is a continuation in part of U.S. application Ser. No.12/238,941, filed Sep. 26, 2008, now U.S. Pat. No. 8,118,826. U.S.application Ser. No. 12/790,313 is also a continuation in part of U.S.application Ser. No. 12/239,129, filed Sep. 26, 2008, now U.S. Pat. No.8,118,736. Application Ser. Nos. 12/790,313, 12/238,941 and 12/239,129claim priority to U.S. provisional application 60/975,548, filed Sep.27, 2007 and to U.S. provisional application 61/038,457, filed Mar. 21,2008. The subject matter of all of these prior applications is fullyincorporated herein by this reference.

FIELD OF THE INVENTION

This invention relates to creating, maintaining and using a surgicalpathway between the bladder and the exterior abdomen of a patient. Moreparticularly, the present invention relates to a new and improvedapparatus and method for performing a cystotomy for medical proceduressuch as inserting a cannula to facilitate surgical access to the bladderor inserting a catheter to facilitate urine drainage, in a manner whichminimizes trauma experienced by the patient and promotes efficientlyperforming the procedure.

BACKGROUND OF THE INVENTION

A cystotomy is a surgical procedure which cuts or forms a surgicalpathway between the bladder and the exterior abdomen through theintervening abdominal tissue. A cystotomy establishes access to theinterior of the bladder. A cannula is inserted into the surgical pathwayto create an access pathway for inserting medical instruments into thebladder. A variety of different medical procedures can be performedinside the bladder using the instruments inserted through the cannula.

A cystostomy is a surgical procedure which cuts or forms a surgicalpathway between the bladder and the exterior abdomen through theintervening abdominal tissue for the purpose of establishing anadditional urine drainage pathway from the bladder, such as when theurine flow path through the natural urinary canal is inhibited orobstructed. Once the surgical pathway has been formed, a hollow tubularurine drainage catheter is inserted in the surgical pathway. Urine isdrained from the bladder through the catheter. The catheter initiallyremains in place long enough for the surrounding tissue to form a tractor sinus between the bladder and the exterior abdomen. Thereafter, thecatheter is replaced periodically in order to help prevent infection. Acystostomy is typically required when urine flow is blocked by swellingof the prostate (benign prostatic hypertrophy), traumatic disruption ofthe urethra, congenital defects of the urinary tract, obstructions suchas kidney stones passed into the urethra, or cancer. A cystostomy isalso a common treatment used among spinal cord injury patients who areunable or unwilling to use intermittent catheterization to empty thebladder and cannot otherwise void due to detrusor sphincter dyssynergia.

In both a cystotomy and a cystostomy, a surgical pathway is createdbetween the bladder and the exterior abdomen through the interveningabdominal tissue. Because of the common aspects of forming the surgicalpathway, the term “cystotomy,” as used herein, will refer to forming thesurgical pathway between the bladder and the exterior abdomen throughthe intervening abdominal tissue, regardless of whether a catheter isinserted in the surgical pathway as an auxiliary urine drainagepassageway or a cannula is inserted in the surgical pathway to receiveand accept surgical instruments for performing a medical procedurewithin the bladder.

There are two general techniques for performing a cystotomy. An“outside-in” cystotomy, sometimes referred to as a percutaneouscystostomy, is performed by cutting the surgical pathway from theexterior abdomen through the intervening abdominal tissue into thebladder. An “inside-out” cystotomy is sometimes referred to as atransurethral cystotomy because access to the interior of the bladder isachieved through the urinary canal. An inside-out a cystostomy isperformed by cutting the surgical pathway from the bladder through theintervening abdominal tissue to the exterior abdomen.

An outside-in cystotomy typically involves the insertion of a needlefrom the exterior abdomen to inside the bladder. The insertion of theneedle through the abdomen creates a surgical pathway into the bladder.A sheath surrounding the needle is kept within the surgical pathway whenthe needle is removed. Outside-in cystotomies are suitable for drainingurine from the bladder, but are not typically suitable for performingmedical procedures within the bladder because the small diameter size ofthe sheath is insufficient to accommodate medical instruments. Onedifficulty or disadvantage associated with outside-in cystostomies isthe potential to puncture through the posterior wall of the bladdercreating fistulas.

An inside-out cystotomy involves the use of a medical instrument calleda sound. The sound is inserted through the urinary tract and is pushedagainst the bladder. The surgical pathway is then formed by forcing thesound from the bladder through the intervening tissue to the externalabdomen. An inside-out cystotomy is generally considered a blindprocedure because the surgeon lacks a precise visual indication of thelocation of the end of the sound within the bladder, unless a bulge onthe abdomen can be created. It is typically impossible to tent or bulgethe exterior abdomen of obese patients, because of the excess abdominaltissue. Instead, the surgeon generally must rely on personal skill andexperience to position the sound and predict the location where thecutting blade will emerge.

All cystotomies carry some risk of complication. Potential complicationsfrom performing a cystotomy involve accidentally cutting the intestine.The intestines are located very close to the location where the surgicalpathway is normally established. Furthermore, different patients haveslightly different anatomies which makes it difficult to predict exactlythe location of the intestines in the intervening tissue between thebladder and the external abdomen, particularly in the case of obesepatients. Generally, imaging is not used during the procedure. Thedangers from infection due to even a small and unintentional cut of theintestine are substantial, and a not-insignificant number of suchincidents can result in death. Nevertheless, a cystotomy may be the onlyoption for use with some patients who have greater risks of othermedical problems resulting from not performing the cystotomy, or acystotomy may be required or desirable as part of another surgicalprocedure.

To minimize the possibility of inadvertently cutting the intestine andto otherwise reduce tissue trauma, and because the sound must have asize capable of being inserted through the urinary tract, the cuttingtip used to create the surgical pathway is relatively small in size. Thesmall size helps to reduce the possibility of cutting adjacent tissues,such as the intestines. If a cannula is to be inserted within thesurgical pathway, the surgical pathway must be expanded to accept thelarger cannula. It is desirable to expand the size of the initialsurgical pathway without unduly tearing the tissue and without inducingmore trauma. It is also desirable to facilitate the use of medicalequipment to perform the cystotomy, thereby reducing the time durationof the medical procedure and the trauma to the patient.

Additionally, known instruments currently available for use incystotomies have no capability for effectively securing the bladder wallduring the procedure, allowing for the possibility that the flaccid wallof the bladder may impede the procedure.

SUMMARY OF THE INVENTION

The present invention involves improvements in the medical equipmentused to perform a cystotomy, thereby improving the chances of asuccessful medical result while minimizing trauma to the patient andminimizing risks to the medical personnel who perform the procedure. Thenew and improved features of the apparatus and methodology describedherein enhance the accuracy of creating the surgical pathway at thedesired location, facilitate the maintenance and expansion of thesurgical pathway after it has been created, secure the bladder wall toavoid impeding the procedure, minimize risks to the surgeon and medicalpersonnel of being accidentally cut by the cutting tip, permit theinsertion of a dilator and cannula into the surgical pathway withgreater ease to the surgeon and less trauma to the patient, provide morereliable indications of the extent of movement required to cut thesurgical pathway and to insert a dilator and a cannula, minimizeadditional cutting or tearing of patient tissue surrounding the surgicalpathway while expanding the surgical pathway, maintain the distal tip ofthe sound within the bladder and within the surgical pathway, maintainthe dilator and cannula in the surgical pathway without permittinginadvertent movement out of the surgical pathway, avoid accidentallyallowing the surgical pathway to close after it has been created, andgenerally facilitate better and more effective cystotomies, among otherthings.

In accordance with these and other features, one aspect of thisinvention relates to a cystotomy apparatus for creating a surgicalpathway from a bladder through abdominal tissue to an exterior abdomen.The cystotomy apparatus includes a sound for insertion through a urinarytract into the bladder. The sound defines a passageway which extendsfrom its distal end to its proximal end. A handle portion is connectedto the proximal end of the sound at a position which remains exterior tothe urinary tract. The handle portion is adapted for manipulating thedistal end of the sound adjacent to a position where the surgicalpathway is to be created. A cutting tip having a blade for cuttingthrough tissue to create the surgical pathway is connected to anadvancement device by the complementary interaction of a cutting tipconnector on the cutting tip and an advancement device connector on theadvancement device. The advancement device is longitudinally moveablewithin the passageway of the sound. The distal end of the sound extendsthe distal end of the advancement device and the connected cutting tipin a predetermined path from the distal end of the sound when thesurgical pathway is created. A capture cup has a containment area forreceiving and holding the cutting tip. An alignment structure isconnected to the handle portion and includes a retaining portion forreleasably retaining the capture cup at a position exterior to theabdomen in alignment with the predetermined path. Retained in thismanner, the containment area of the capture cup receives the cutting tipafter the surgical pathway has been created by longitudinal movement ofthe advancement device and the connected cutting tip.

Subsidiary features of the cystotomy apparatus of the invention includebayonet style connections formed by the advancement device connector andcutting tip connector, an adjustable portion of the alignment structureto adjust the position of the capture cup along the predetermined pathrelative to the distal end of the sound, a bayonet style connectionbetween the retention portion of the alignment structure and the capturecup to detach the capture cup from the retaining portion whilesimultaneously detaching the alignment structure connector and thecutting tip connector, an elastomeric lining within containment area ofthe capture cup to frictionally engage the cutting tip upon movement ofthe cutting tip into the containment area and to transfer rotationalforce from the capture cup to the cutting tip through the elastomericlining to detach the cutting tip from the distal end of the advancementdevice, a lock wire longitudinally moveable within the internalpassageways of the advancement device connector and the cutting tipconnector to separate an alternative embodiment of the connectors, aninflatable balloon positioned at the distal end of the sound which in aninflated state protrudes radially outward from the distal end of thesound a sufficient distance to impede the distal end of the sound frommoving into the surgical pathway, a metal ribbon wound in alongitudinally extending helical coil to form a portion of theadvancement device, a plurality of rods positioned within an internalpassageway defined by the helical coil to enhance transfer forcecapability of the advancement coil when moving longitudinally to createthe surgical pathway, a gap which separates adjacent portions of asemicircular wall structure of the retention portion of the alignmentstructure through which distal end of the advancement device may bepassed without disconnecting the alignment structure from the handle, anannular groove around the capture cup to receive the semicircular wallstructure of the retention portion to retain the capture cup, a roundedend piece attached to the distal end of the sound which covers thepassageway of the sound and facilitates movement of the distal end ofthe sound through the urinary tract and through which the blade of thecutting tip cuts upon longitudinal advancement of the cutting tip out ofthe distal end of the passageway of the sound, and an inverted funnelshape located in the capture cup to direct the cutting tip into thecontainment area after the surgical pathway is created.

Other subsidiary features involve using a dilator in combination withthe cystotomy apparatus. The dilator is inserted into the surgicalpathway. The dilator includes a stylet which has a stylet connector at adistal end that is adapted to connect with the advancement deviceconnector after removal of the cutting tip. The advancement device ismoved in a proximal longitudinal direction to move the dilator and theconnected stylet through the surgical path until the stylet connectorand the advancement device connector are located within the bladder, atwhich point the stylet disconnects the stylet connector from the deviceconnector within the bladder.

Other subsidiary features involve using a cannula in combination withthe dilator after the dilator is located in the surgical pathway. Thecannula includes a cannula tube which defines an internal passageway forinserting and manipulating medical instruments. An obturator includes ashaft adapted to be removably received within the internal passageway ofthe cannula tube by insertion through a center opening of the dilator.The dilator operatively expands to accommodate the cannula tube and theshaft of the obturator as the cannula and the obturator are moved intothe center opening of the dilator, thereby expanding the surgicalpathway.

Another aspect of the invention relates to a method of creating thesurgical pathway using the cystotomy apparatus. The method involvesinserting the sound through the urinary tract until a distal end of thesound abuts the bladder at a position where the surgical pathway is tobe created, adjusting the alignment structure to position the capturecup on the external abdomen in alignment with the predetermined path,longitudinally moving the advancement device and the connected cuttingtip through the bladder and the abdominal tissue to the external abdomento create the surgical pathway, continuing longitudinally moving theadvancement device until the cutting tip is received within the capturecup, disconnecting the capture cup from the alignment structure, anddisconnecting the cutting tip from the advancement device while thecutting tip is retained within the capture cup.

Subsidiary features of the method of forming the surgical pathwayinclude disconnecting the capture cup from the alignment structuresimultaneously with disconnecting of the cutting tip from theadvancement device, retaining the distal end of the sound to avoidprojecting the distal end of the sound into the surgical pathway byinflating an inflatable balloon on a distal end of the sound when thedistal end of the sound is within the bladder and before the advancementdevice and connected cutting tip are longitudinally moved to create thesurgical pathway, removing the alignment structure from the connectedrelationship with the handle portion of the sound by passing equipmentextending into the surgical pathway through a gap in the retainingportion of the alignment structure, determining the distance from thebladder through the abdominal tissue to the external abdomen along whichthe surgical pathway is created by reference to indicia formed on thealignment structure, and longitudinally moving the advancement deviceand the cutting tip to create the surgical pathway by a distance atleast equal to the distance from the bladder through the abdominaltissue to the external abdomen by reference to indicia formed on thesound.

Another aspect of the method of creating a surgical pathway involvesexpanding the surgical pathway using the dilator, by extending thestylet through the dilator, connecting the stylet connector to theadvancement device connector after removing the cutting tip, andlongitudinally moving the advancement device to move the connectedstylet and dilator into the surgical pathway. A further subsidiaryaspect involves determining the length of the surgical pathway from thebladder through the abdominal tissue to the external abdomen byreference to indicia formed on the alignment structure, andlongitudinally moving the advancement device with the connected styletby a distance at least equal to the distance from the bladder throughthe abdominal tissue to the external abdomen by reference to indiciaformed on the dilator.

A further aspect of the method of creating the surgical pathway involvesinserting a cannula in the dilator, by removing the stylet from thedilator after the dilator has been positioned within the surgicalpathway, inserting an obturator into a cannula tube of a cannula,inserting a distal end of the cannula tube with the obturator insertedinto the cannula tube into the dilator after the dilator has beenpositioned within the surgical pathway, expanding the surgical pathwayby insertion of the cannula tube and obturator into the dilator, andremoving the obturator from the cannula. A further subsidiary feature ofthis aspect of the method involves inserting a medical instrumentthrough the cannula tube from the exterior of the patient and into thebladder, and performing a medical procedure within the bladder using themedical instrument inserted through the cannula tube.

Another aspect of the invention involves a dilator for inserting acannula into a surgical pathway extending between a bladder and anexternal abdomen. The dilator includes a body which is located outsideof the abdomen. A ring portion of the body defines a central openingabout a central axis through which the cannula is inserted. A pluralityof arm receivers are connected to the ring portion on opposite sides ofthe central axis. A plurality of substantially straight and elongatedarms are connected to and extend distally from each arm receiver. Eacharm has a central passageway which extends substantially along thelength of the arm. Each arm defines a window into the central passagewayfacing outward from the central axis at a position adjacent to thedistal end of each arm. A longitudinal tab member is positioned withinthe central passageway of each arm. The longitudinal tab member extendsfrom a distal end located at the distal end of the arm past the windowto a proximal end located in the arm receiver. A wing member is attachedto the proximal end of the longitudinal tab member. The wing member ismovably positioned in a longitudinally extending slot formed in the armreceiver. The wing member is movable in the slot in distal and proximaldirections to move the portion of the longitudinal tab member which isproximal to the window in distal and proximal directions within thecentral passageway. A portion of the longitudinal tab adjacent to thewindow including stress risers adjacent to deflection portions of thelongitudinal tab member. The stress risers direct the deflectionportions to protrude outwardly through the window upon longitudinaldistal movement of the longitudinal tab member by the wing member and towithdraw the deflection portions into the window upon longitudinalproximal movement of the longitudinal tab member by the wing member. Thecentral passageway of each arm extend substantially straight between thewindow and the proximal end of each arm. The proximal and distalmovement of the wing member in the slot occurring in substantiallystraight alignment with the portion of the longitudinal tab memberextending in the center passageway of each arm.

Other subsidiary features of the dilator of the present inventioninclude indicia formed at intervals along at least one arm to indicatethe depth of movement of the dilator into the surgical pathway, a loopconnected at distal end of the arms on opposite sides of the centralaxis with each loop extending toward the central axis and the loopsoccupying respectively different longitudinal positions on the arms toallow the loops to overlap upon transverse inward deflection of the armstoward the central axis.

Another aspect involves combining the dilator with a stylet whichcomprises a shaft having a longitudinal length that is greater than thelength of the arms of the dilator. A stylet connector is formed on adistal end of the shaft to releasably connect with a complementaryconnector of a device located in the surgical pathway. The shaft of thestylet extends through the center opening along the central axis withthe distal end of the shaft of the stylet extending through theoverlapped loops on the distal ends of the arms to hold the armsdeflected transversely inwardly during insertion of the dilator in thesurgical pathway. Subsidiary features of the dilator include sidecavities formed on opposite transverse sides of the central passageway,and forming the loops by a wire curved in the form of a loop having endsextending into the side cavities. The ends of the wire extendsubstantially the entire length of each arm. A knob at a proximal end ofthe shaft of the stylet includes a connector which connects in acomplementary manner with a connector on the ring portion, uponinsertion of the stylet through the center opening and the distal end ofthe shaft through the overlapped loops. The complementary connectorsbetween the knob and the ring portion and between the distal end of theshaft and the device in the surgical pathway release from one another bymovement of the knob relative to the ring portion.

Another aspect of the invention involves combining the dilator with thecannula. The cannula comprises a cannula tube which defines an internalpassageway for inserting and manipulating medical instruments. Anobturator includes an obturator shaft which is adapted to be removablyreceived within the internal passageway of the cannula tube. Theobturator shaft has a distal end of tapered and rounded shape whichprotrudes beyond the distal end of the cannula tube. The center openingof the dilator receives the cannula tube and the obturator insertedwithin the cannula tube, causing the arms of the dilator to expandtransversely to accommodate the cannula tube and the obturator shaft asthe cannula and the obturator move distally into the center opening ofthe dilator. The expansion of the arms to accept the cannula and theobturator also expanding the surgical pathway. Subsidiary featureinvolves a proximal body portion of the cannula having a complementaryconnector for connecting with a connector on the ring portion of thedilator upon insertion of the cannula through the center opening of thedilator.

A more complete appreciation of the present invention and its scope maybe obtained from the accompanying drawings, which are briefly summarizedbelow, from the following detailed description of presently preferredembodiments of the invention, and from the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a suprapubic cystotomy apparatus of thepresent invention.

FIG. 2 is a longitudinal cross-sectional view of the apparatus shown inFIG. 1.

FIG. 3 is a longitudinal cross-sectional view of a rear handle and itsconnection to an advancement device of the apparatus shown in FIG. 1.

FIG. 4 is a partial perspective and sectioned view of the rear handleshown in FIG. 3.

FIG. 5A is a longitudinal cross-sectional view of a front handle and alocking mechanism of the apparatus shown in FIG. 1, shown in a lockedposition.

FIG. 5B is a longitudinal cross-sectional view similar to that shown inFIG. 5, showing an unlocked position of the locking mechanism.

FIG. 6A is a side elevational view of the advancement device showing anadvancement coil connected to an advancement rod.

FIG. 6B is an expanded portion of the advancement device shown in FIG.6A, with a portion broken out.

FIG. 7 is a partial longitudinal cross-sectional view of a sound of theapparatus shown in FIG. 1, showing a cutting tip connected to theadvancement coil located at a distal end of the sound.

FIG. 8 is an exploded partial perspective view of the advancement coiland the cutting tip shown in FIG. 7, illustrating a bayonet connectionof the advancement coil and the cutting tip.

FIG. 9 is an exploded perspective view of the details of aninterdigitated connection between the advancement coil and the cuttingtip, which constitutes an alternative to the connection shown in FIGS. 7and 8.

FIG. 10 is a longitudinal and broken out cross-sectional view of theinterdigitated connection between the advancement coil and the cuttingtip shown in FIG. 9, and its interaction with an alternative embodimentof the rear handle of the apparatus shown in FIG. 1.

FIG. 11 is a partial longitudinal cross-sectional view of a curvedportion of the sound and of the advancement coil contained in thatcurved portion of the apparatus shown in FIG. 1.

FIG. 12 is a transverse cross-sectional view of another embodiment ofthe advancement coil of the apparatus shown in FIGS. 1 and 11,containing a plurality of small diameter rods.

FIG. 13 is a partial longitudinal cross-sectional and perspective viewof a distal end of the sound of the apparatus shown in FIGS. 1 and 7,illustrating an inflatable balloon.

FIG. 14 is a partial longitudinal cross-sectional view of a capture cupand funnel housing connected to a distal end of a guide arm of theapparatus shown in FIG. 1, illustrating the cutting tip advanced intothe capture cup.

FIG. 15 is an exploded perspective view of the capture cup, funnelhousing and a portion of the guide arm shown in FIG. 14.

FIG. 16A is a perspective exploded view of another embodiment of thecapture cup and guide arm compared to that shown in FIGS. 14 and 15,illustrating a portion of the capture cup broken out and a distalportion of the guide arm.

FIG. 16B is a perspective exploded view of another embodiment of thecapture cup and guide arm compared to that shown in FIGS. 14 and 15 andin FIG. 16A, illustrating a portion of the capture cup broken out and adistal portion of the guide arm.

FIGS. 17-22 are partial cross-sectional and perspective views showing aseries of actions involved in using the apparatus shown in FIGS. 1-16 ina cystotomy to cut a surgical pathway from the bladder to the exteriorabdomen in a patient. More specifically, FIG. 17 shows inserting thesound through the urinary tract into the bladder;

FIG. 18 shows pressing the distal end of the sound against the bladderand tissue between the bladder and the exterior abdomen along with theguide arm and capture cup above a tented or bulged area of the exteriorabdomen;

FIG. 19 shows moving the guide arm downward along the mast to positionthe capture cup on the exterior abdomen at the tented or bulgedlocation;

FIG. 20 shows expanding a balloon on the distal end of the sound tomaintain the distal end of the sound within the bladder and preventingit from entering the surgical pathway;

FIG. 21 shows advancing the cutting tip from the distal end of the soundthrough the bladder into the tissue between the bladder and the externalabdomen while creating the surgical pathway; and

FIG. 22 shows completion of the surgical pathway by advancement of thecutting tip into the capture cup and rotation of the capture cup toremove it from the guide arm and to remove the cutting tip from theadvancement coil.

FIG. 23 is an exploded perspective view of a dilator and a stylet of thepresent invention used with the dilator, both of which are inserted intothe surgical pathway between the bladder and abdomen created as shown inFIG. 22, by use of the apparatus shown in FIG. 1.

FIG. 24A is a longitudinal cross-sectional view of an arm of the dilatorshown in FIG. 23.

FIG. 24B is a transverse cross-sectional view of the arm shown in FIG.24A, taken substantially in the plane of line 24B-24B.

FIG. 24C is a perspective view of a longitudinal tab and wing of thedilator shown in FIG. 23, removed from the dilator with a distal portionof the longitudinal tab shown in an expanded condition.

FIG. 24D is a perspective view of a wire and loop formed in the wireshown in FIGS. 23 and 24A, removed from the arm of the dilator.

FIG. 25A is a perspective view of the dilator and the stylet shown inFIG. 23, illustrated in a connected together relationship, with anenlarged portion of a distal end of the connected dilator and stylet.

FIG. 25B is an enlarged perspective view of a portion of the dilatorshown in FIG. 25A.

FIGS. 26-32 are partial cross-sectional and perspective views showing aseries of actions involved in using the dilator and stylus shown inFIGS. 23-25 along with the apparatus shown in FIGS. 1-16 to maintain thesurgical pathway completed as shown in FIG. 22, with the dilator andstylus having a greater scale in proportion to the other aspects ofFIGS. 26-32. More specifically, FIG. 26 shows the dilator and styletconnected to the advancement coil of the sound of the apparatus shown inFIG. 1;

FIG. 27 shows moving the dilator and stylet into the surgical pathway byretraction of the advancement coil;

FIG. 28 shows anchoring the distal end of the dilator in the bladder;

FIG. 29 shows disconnecting the dilator and stylet from the advancementcoil within the bladder;

FIG. 30 shows the dilator and stylet in the surgical pathway afterremoval of the sound from within the bladder and urinary tract;

FIG. 31 shows removing the stylet from the dilator; and

FIG. 32 shows the dilator anchored in the bladder after removing thestylet.

FIG. 33 is a perspective view of a cannula of the present invention usedin conjunction with the dilator shown in FIGS. 23-32.

FIG. 34 is a perspective view of an obturator of the present inventionused in conjunction with the cannula shown in FIG. 33 to insert thecannula into the dilator shown in FIG. 23.

FIG. 35 is a perspective view of the cannula shown in FIG. 33 into whichthe obturator shown in FIG. 34 has been inserted and connected.

FIGS. 36-38 are partial cross-sectional and perspective views showing aseries of actions involved in inserting the cannula and obturator shownin FIGS. 33-35 into the dilator shown in FIGS. 23 and 32 to expand thesurgical pathway, with the cannula, obturator and dilator having agreater scale in proportion to the other aspects of FIGS. 36-38. Morespecifically, FIG. 36 shows inserting the connected cannula andobturator into the dilator during expansion of the surgical pathway;

FIG. 37 shows the connected cannula and obturator fully inserted intothe dilator and complete expansion of the surgical pathway; and

FIG. 38 shows removing the obturator from the dilator.

FIG. 39 is a perspective view of the cannula within the dilator afterthe obturator has been removed, in the condition shown in FIG. 38.

FIG. 40 is a partial cross-sectional and perspective illustrationshowing the cannula within the dilator as illustrated in FIG. 39 in acondition of use.

FIG. 41 is a partial cross-sectional and perspective illustration ofinserting a medical instrument into the cannula connected to the dilatoras illustrated in FIG. 40.

DETAILED DESCRIPTION

A cystotomy apparatus 20 which embodies a portion of the presentinvention is shown in FIGS. 1 and 2. The apparatus 20 is used to performa cystotomy (FIGS. 17-22) and related procedures (FIGS. 26-29) on apatient. A sound 22 of the apparatus 20 is inserted though a urethra orurinary tract 24 and into a bladder 26 of the patient (FIGS. 17-22,26-32, 36-38, 40 and 41). The surgeon manipulates a proximal portion ofthe apparatus 20 to position a distal end 28 of the sound against thebladder 26 at a location where a surgical pathway 29 (FIGS. 21 and 22)is cut from the bladder 26 through intervening tissue to an externalabdomen 30 of the patient (FIGS. 17-22).

The relative terms “proximal” and “distal” are used herein to describeaspects of the apparatus 20 in relation to the medical practitioner whoinserts the sound 22 into the urinary tract 24 at the exterior openingof the urinary tract 24. Accordingly, the portions of the apparatus 20which are the most internal within the patient and are therefore moreremoved from the surgeon are referred to as “distal,” and the portionsof the apparatus 20 which are closest to the exterior opening of theurinary tract 24 and the surgeon are referred to as “proximal.” Thissame convention applies with respect to those portions of the apparatus20 which are not within the urinary tract 24, (e.g. guide arm 154) inthe sense that those external portions which are more removed from thesurgeon are referred to as “distal” and the portions which are closer tothe surgeon are referred to as “proximal.”

The sound 22 comprises a rigid hollow tube 32 which contains anadvancement device 34. The advancement device 34 is shown in greaterdetail in FIG. 6, and includes a distal advancement coil 35 which iswelded to a proximal advancement rod 37. The rigid hollow tube 32 has amoderate curved portion 36 close to the distal end 28. The curvedportion 36 facilitates directing the distal end 28 of the sound 22 intoan advantageous position where the surgical pathway 29 is to be created,in conformance with the anatomy of the patient. The advancement device34 is axially moveable within a center passageway 38 of the tube 32. Theadvancement coil 35 is flexible enough to bend around the curved portion36 of the rigid hollow tube 32, when the advancement device 34 isadvanced and retracted within the tube 32. The characteristics of theadvancement coil 35 limit the contraction of the advancement coil 35 inan axial or longitudinal direction, despite its flexibility in atransverse direction. The advancement rod 37 of the advancement deviceis straight and rigid. The advancement rod 37 does not enter or movewithin the curved portion 36 of the rigid hollow tube 32, when theadvancement device is moved longitudinally in the center passageway 38of the tube 32.

A cutting tip 40 is attached to a distal end 42 of the advancement coil35. The cutting tip 40 includes a blade 41 (FIGS. 7 and 8) which cutsthrough the intervening tissue between the bladder 26 and the exteriorabdomen 30. The cutting tip 40 is advanced out of the distal end 28 ofthe sound 22 and is pushed through the bladder 26, the interveningtissue and out of the external abdomen 30 to create the surgical pathway29 (FIGS. 21 and 22), after the distal end 28 of the sound 22 ispositioned against the bladder 26 (FIG. 18). Force is applied to theproximal end of the advancement device 34 at the proximal end of theapparatus 20 outside of the patient, to advance the advancement device34 through the rigid hollow tube 32 and force the cutting tip 40 throughthe tissue to create the surgical pathway 29. The cutting tip 40 movesalong a path 46 which extends generally in alignment with a straightportion 47 of the tube 22 which is located between the curved portion 36and the distal end 28 of the sound 22. The advancement coil 35 issufficiently rigid in the transverse dimension to maintain the distalend 42 aligned and coaxial with the path 46 when advanced the distal end42 is advanced from the distal end 28 of the sound 22 and the cuttingtip 40 is pushed through the bladder 26, the intervening tissue and outof the external abdomen 30.

The sound 22 is connected to a proximal portion of the apparatus 20which is located outside of the urinary tract 24. The proximal portionof the apparatus which is located exterior of the patient includes afront handle 48 and a rear handle 50. The surgeon grasps one or both ofthe handles 48 and 50 when manipulating the sound 22 in the urinarytract 24 and the bladder 26.

The rear handle 50 is slidably mounted on a tubular body 52 whichextends proximally from the front handle 48. The passageway 38, whichcontains the advancement device 34, extends from the distal end 28 ofthe sound, through the front handle 48 and through the tubular body 52.A proximal end 54 of the advancement rod 37 is connected to a connectorplate 56 within the rear handle 50, as shown in FIGS. 3 and 4. A narrowslot 58 extends along the tubular body 52 and creates enough clearancefor the connector plate 56 to extend into the passageway 38 where it isconnected to the proximal end of the advancement rod 37, while allowingthe rear handle 50 to move along the tubular body 52. The rear handle 50is moved toward and away from the front handle 48 to advance and retractthe advancement device 34 within the passageway 38, respectively. Theextension and retraction of the advancement device 34 extends andretracts the cutting tip 40 relative to the distal end 28 of the sound22. The connector plate 56 residing within the slot 58 prevents the rearhandle 50 from rotating relative to the tubular body 52.

Indicia 62 are formed on the sound 22 to indicate distance from thedistal end 28 of the sound 22, as shown in FIG. 1. The indicia 62 areused to determine the length of the sound 22 which is inserted into theurinary tract 24 (FIGS. 17-22), by observing the indicia 62 closest toan exterior opening 64 of the urinary tract 24. To facilitateidentifying the length of the sound 22 inserted into the urinary tract24 and bladder 26, an indicator slide 66 is moved adjacent to theexternal opening 64 of the urinary tract 24 (FIG. 20). Movement of theindicator slide 66 to the position adjacent the external opening 64allows the surgeon to readily determine whether the position of thesound within the urinary tract 24 and bladder 26 has changed from theinitial desired position during the course of the procedure.

Indicia 68, shown in FIG. 1, are formed on the tubular body 52 toindicate a distance that the cutting tip 40 has been extended from thedistal end 28 of the sound 22. The distance that the cutting tip 40 isextended from the distal end 28 of the sound 22 is determined byobserving the location of the rear handle 50 relative to the indicia 68before distal movement of the rear handle 50 to advance the advancementdevice 34 and the connected cutting tip 40, observing the location ofthe rear handle 50 relative to the indicia 68 during the distal movementof the rear handle 50, and determining the difference between the twoindicia. The difference between the two indicia represents the amount ofadvancement of the cutting tip 40. The ability to determine the amountof advancement of the cutting tip 40 is important in determining whetherthe cutting tip 40 has created a surgical pathway of sufficient lengthto extend from the bladder 26 to the external abdomen 40.

A locking mechanism 72 of the front handle 48 selectively locks theadvancement device 34 in a desired advanced or retracted position withinthe passageway 38, as shown in FIGS. 5 and 6. The locking mechanism 72comprises a rotatable brake wheel 74 which is movable between a lockedposition (FIG. 5) and an unlocked position (FIG. 6). A pair of brakespring arms 76 are mounted in the front handle 48 on opposite sides ofthe advancement rod 37 of the advancement device 34. The brake springarms 76 are preferably formed from a single piece of spring steel havinga bridge portion between the spring arms 76 with a hole though thebridge portion to accept the advancement rod 37. Ends 78 of the brakespring arms 76 are biased to contact the advancement device 34 in thelocked position. Evenly-spaced circumferential notches 80 are spacedapart along the circumference of a length of the advancement rod 37which passes adjacent to the ends 78 of the brake spring arms 76. Thenotches 80 are each wide enough to receive the ends 78 of the brakespring arms 76. The advancement device 34 is locked in position when theends 78 of the brake spring arms 76 are received in one of thecircumferential notches 80.

A cam member 82 is formed on the brake wheel 74 to contact and bend theends 78 of the brake spring arms 76 away from and out of the notches 80of the advancement rod 37, when the brake wheel 74 is rotated into theunlocked position (FIG. 6). The shape of the cam member 82 maintains thebrake wheel 74 in the unlocked position once rotated into the unlockedposition, without requiring continuous external force to hold the brakewheel 74 in the unlocked position. The axial movement of the advancementdevice 34 is not impeded by the brake spring arms 76 when the brakewheel 74 is in the unlocked position.

When the brake wheel 74 is rotated into the locked position (FIG. 5)from the unlocked positioned (FIG. 6), the ends 78 of the brake springarms 76 move into at least one circumferential notch 80. If the ends 78contact the advancement rod 37 of the advancement device 34 at alocation between two circumferential notches 80, the ends 78 will slideinto an adjacent one of the notches 80 with further slight distal orproximal movement of the rear handle 50, thereafter locking theadvancement device 34 in place. The ability to lock the advancementdevice 34 in a desired position, and therefore establish a desiredposition of the cutting tip 40, is a convenience to the surgeon forholding the position of the cutting tip 40 at different stages of theprocedure, without requiring continual manual force to hold the desiredposition. Although not shown, a cap may be hinged to the front handle 48to selectively pivot and cover and uncover the brake wheel 74. When thecap is pivoted into the position covering the brake wheel 74,manipulation of the handle 48 will not accidentally move the brake wheel74 into an unlocked position.

The distal end 28 of the rigid hollow tube 32 is capped with asemispherical soft sheath 84 before use, as shown in FIG. 7. Thesemispherical soft sheath 84 provides a rounded or curved forwardmostend on the distal end 28 of the sound 22, which facilitates guiding thedistal end 28 of the sound 22 through the urinary tract 24. The curvedforwardmost end created by the soft sheath 84 helps to prevent trauma tothe urinary tract 24 (FIG. 17) which might otherwise occur, if theforwardmost end of the distal end 28 of the sound 22 was open andinserted into the urinary tract 24, for example. The sheath 84 is alsouseful to prevent unnecessary trauma to the bladder 26 when the surgeonprobes the bladder to locate the desired position for creating thesurgical pathway. The sheath 84 is formed from material such assilicone, which is readily pierced when the cutting tip 40 is extended.

The pathway 38 at the distal end 28 of the rigid hollow tube 32 of thesound 22 includes an increased diameter portion 86 to accommodate thecutting blade 41 of the cutting tip 40. The cutting tip 40 includes acutting tip connector 88 which connects with an advancement deviceconnector 90 formed on the distal end 42 of the advancement coil 35. Theinteraction of the cutting tip connector 88 and the advancement deviceconnector 90 releasably connects the cutting tip 40 to the advancementcoil 35, as shown in FIGS. 7 and 8.

The advancement device connector 90 includes a tubular wall 92 whichdefines a receptacle 94, as shown in FIGS. 7 and 8. The cutting tipconnector 88 includes a cylindrical main body 96 sized to closely fitwithin the receptacle 94. A spiral shaped entry slot 98 is formed intothe tubular wall 92. The entry slot 98 extends from an opening 100 at adistal end 102 of the tubular wall 92 to an end 104 located proximallyfrom the distal end 102. A bayonet finger 106 extends radially outwardfrom a small portion of a base 108 of the cylindrical main body 96. Toconnect the cutting tip connector 88 to the advancement device connector90, the base 108 of the cylindrical main body 96 is coaxially alignedwith the receptacle 94 and the bayonet finger 106 is axially alignedwith the slot opening 100. The cylindrical main body 96 is then pushedinto the receptacle 94 as the bayonet finger 106 enters the entry slot98. The main body 96 is rotated relative to the receptacle 94 until thebayonet finger 106 abuts against the slot end 104. The cutting tipconnector 88 is disconnected from the advancement device connector 90 byreversing this action.

The cutting tip connector 88 and the advancement device connector 90described above are bayonet-style connectors. Other types of connectorsmay be used to connect the cutting tip 40 to the advancement coil 35.One other type of connector is created by interdigitated cutting tip andadvancement device connectors 110 and 112, respectively, shown in FIGS.9 and 10. Both connectors 110 and 112 have cylindrical bodies 114 and116 with mating ends 118 and 120, respectively. The mating ends 118 and120 interconnect with one another to connect the cutting tip 42 and thedistal end 42 of the advancement coil 34.

The mating ends 118 and 120 each have deep radially-extending recesses122 adjacent to a shallow radially-extending recesses 124 formed intosides of the cylindrical bodies 114 and 116. The shape of each deeprecess 122 is complementary to the shape of each shallow recess 124formed on the other mating end 118 and 120. The deep recesses 122 ofeach mating end 118 and 120 mate with the complementary shallow recesses124 of the other mating end 118 and 120. The mating ends 118 and 120laterally connect to axially align the cylindrical bodies 114 and 116 asa continuous cylinder when the complementary recesses 124 and 122 fittogether, as shown in FIG. 10.

To keep the mating ends 118 and 120 together in the connected positionshown in FIG. 10, both cylindrical bodies 114 and 116 have centeropenings 126 which align to form a single continuous center opening whenthe cylindrical bodies 114 and 116 are connected. A lock structure orwire 128 is axially movable within the advancement device 34 and is usedto hold the interdigitated connectors 110 and 112 in theconnected-together and locked-together relationship. The interdigitatedconnectors 110 and 112 are locked together by advancing the lock wire128 into the center openings 126 of the connected together cylindricalbodies 114 and 116. The mating ends 118 and 120 are prevented frommoving laterally with respect to each other, and are thus prevented fromdisconnecting from each other. The mating ends 118 and 120 aredisconnected from each other by retracting the lock wire 128 from thecenter openings 126 and then laterally separating the mating ends 118and 120 from one another. The lock wire 128 extends from the distal end42 of the advancement coil 35 to the proximal end of the advancement rod37 through the passageway 38 of the rigid hollow tube 32 to the rearhandle 50 of the proximal portion of the apparatus 20 (FIG. 1).

Another embodiment of the rear handle 50′, shown in FIG. 10, allows thesurgeon to selectively advance or retract the lock wire 128, and therebyselectively connect or disconnect the interdigitated cutting tip andadvancement device connectors 110 and 112. The rear handle 50′ is formedby a front portion 50A and rear portion 50B. A connector plate 56Aconnects the advancement rod 37 of the advancement device 34 to thefront portion 50A, and a connector plate 56B connects the lock wire 128to the rear portion 50B. Threads 51A and 51B on the exterior of both thefront and rear portions 50A and 50B respectively engage threads 53A and53B on the interior portion of rotatable sleeve 50C. The threads 51A/53Aare reversed with respect to the threads 51B/53B. Rotation of the sleeve50C about the front and rear portions 50A and 50B in one directioncauses the front and rear portions 50A and 50B to move closer togetherand rotation of the sleeve 50C about the front and rear portions 50A and50B in the other direction causes the front and rear portions 50A and50B to move apart.

When the front and rear portions 50A and 50B move closer together withrotation of the sleeve 50C, the lock wire 128 is advanced within theadvancement device 34. When the front and rear portions 50A and 50B movefarther apart with rotation of the cylindrical connector 50C in theopposite direction, the lock wire 128 is retracted within theadvancement device 34. When the sleeve 50C remains stationary withrespect to the front and rear halves 50A and 50B, the front and rearhalves 50A and 50B move in unison to advance or retract the advancementdevice 34 within the passageway 38.

Using the bayonet-style connectors 88 and 90 (FIGS. 7 and 8) rather thanthe interdigitated connectors 110 and 112 (FIGS. 9 and 10) eliminatesthe need for the extra mechanical lock wire 128 and eliminates the needfor multiple parts in the rear handle 50, to connect or disconnect thecutting tip 40 from the advancement coil 35. On the other hand, usingthe interdigitated connectors 110 and 112 rather than the bayonet-styleconnectors 88 and 90 positively locks the interdigitated connectors 110and 112 together, thereby providing assurance that the connectors 110and 112 will not disengage without the affirmative mechanical action ofrotating the sleeve 50C to retract the lock wire 128.

The primary purpose of the advancement device 34 is to advance thecutting tip 40 along a desired linear path 46 through the bladder 26 andthe intervening tissue to the external abdomen 30 (FIGS. 17-22). Theadvancement coil 35 of the advancement device 34 must therefore havesufficient lateral stiffness and strength to avoid substantiallydeviating the path of cutting movement of the cutting tip 40 through thebladder 26 and the intervening tissue to the external abdomen 30,compared to the desired path 46, as the advancement coil 35 is extendedfrom the straight portion 47 of the hollow rigid tube 32 (FIGS. 21 and22). However, the advancement coil 35 must also be flexible enough tobend during movement through the curved portion 36 of the rigid hollowtube 32 (FIGS. 1 and 2) when the advancement coil 35 is advanced orretracted.

To achieve these functional characteristics, the advancement coil 35 isconstructed from a single ribbon or band 81 of metal that is tightlywound in a helical coiled or spiraled manner to form a tube-like shape,as shown in FIG. 11. The band 81 forms a series of adjacent coils 130which continuously abut one another when the advancement coil 35 extendslinearly. The abutting adjacent coils 130 thus resist linearcompression. The resistance to linear compression allows the advancementcoil 35 to transmit enough mechanical force to the cutting tip 40 fromthe rear handle 50 to cut through the bladder 26 and the abdominaltissue to the exterior abdomen 30. Similarly, because of the width ofthe band 81 and its spiral-wound construction, the adjacent coils 130also resist linear expansion. The resistance to linear expansion allowsthe retraction of the advancement coil 35 to retract the cutting tip 40approximately the same distance as the rear handle 50 is moved. In thismanner, the surgeon has excellent control over the degree of extensionand retraction of the cutting tip 40.

The coiled configuration of the band 81 allows the adjacent coils 130 ofthe advancement coil 35 to separate slightly from one another along anoutside arc 132 as the advancement coil 35 moves through the curvedportion 36 of the rigid hollow tube 32, as shown in FIG. 11. The abilityof the individual coils 130 to separate slightly at the outer turnradius of the curved portion 26 allows the advancement coil 35 to bendas necessary without compromising the previously described requirementsfor straight advancement with slight or no deviation from the desiredpath 46 (FIG. 18) when cutting the surgical pathway 29 (FIGS. 21 and22).

If it is desired to further stiffen the advancement coil 35 againstlateral deflection without compromising its capability to move throughthe curved portion 36, the open center area within the advancement coil35, may be filled with small diameter rods 134 of moderate flexibility,shown in FIG. 12. The small diameter rods 134 extend the entire lengthof the advancement coil 35. The rods 134 may extend generally parallelto one another, or the outside rods 134 may be slightly helicallyspiraled with respect to one another.

The small diameter rods 134 may be part of the advancement coil 35 whenthe bayonet-style connectors 88 and 90 (FIGS. 7 and 8) connect thecutting tip 40. However, the lock wire 128 used with the interdigitatedconnectors 110 and 112 could also be used at the center of an outercircumference of rods 134. Under such circumstances, the outercircumference of rods 134 is connected together and the lock wire 128moves relative to the outer circumference of rods 134. Afriction-reducing sheath or surface surrounding the lock wire 128facilitates movement of the lock wire 128 relative to the outercircumference of rods 134.

When the surgical pathway 29 is created through the bladder 26 and theintervening tissue to the external abdomen 30, the distal end 28 of thesound 22 may inadvertently also extend into the surgical pathway, as canbe understood from FIGS. 21 and 22. To eliminate the need for thesurgeon to precisely hold the proximal end of the apparatus 20 while thesurgical pathway 29 is created, and thereby avoid inadvertently movingthe distal end 28 of the sound 22 into the surgical pathway 29, aninflatable balloon 136 is used at the distal end 28 of the sound 22 andthe rigid hollow tube 32, as shown in FIG. 13. The inflatable balloon136 is connected to an inflation tube 138 which extends along the rigidhollow tube 32 from the distal end 28 to near the front handle 48 (FIGS.1 and 2). The inflation tube 138 terminates at its distal end in aconventional fitting (not shown) which allows inflation fluid to bedelivered through the tube 138 and into the balloon 136 for inflatingthe balloon. After inflation, the connection fitting holds the inflationfluid to maintain the balloon 136 in its expanded position shown in FIG.13. The conventional fitting also allows the inflation fluid to beremoved to collapse the balloon 136.

The inflatable balloon 136 is collapsed against the exterior of therigid hollow tube 32 when deflated so as not to impede the insertion ofthe sound 22 through the urinary tract 24. The balloon 136 is inflatedafter the distal end 28 of the sound 22 has been inserted into thebladder 26 and prior to advancing the cutting tip 40 from the rigidhollow tube 32 to create the surgical pathway (FIG. 20). The inflatedballoon 136 presses against the bladder 26 when creating the surgicalpathway from the bladder 26 through the intervening tissue to theexternal abdomen 30 (FIGS. 21-22). Pressing the inflated balloon 136against the bladder 26 surrounding the location of the surgical pathwayprevents the distal end 28 of the sound 22 from extending into thesurgical pathway and possibly even completely through the surgicalpathway.

Extending the distal end 28 of the sound 22 into the surgical pathwaycreates additional trauma and may tear or otherwise distort the surgicalpathway and make use of other equipment during the procedure moredifficult. The restraint from the inflated balloon 136 is particularlyuseful when the rear handle 48 is forced forward to advance the cuttingtip and create the surgical pathway. The force caused by moving the rearhandle 48 forward may be transferred through the apparatus 20, but theinflated balloon 136 resists this effect. Of course, the balloon 136 isdeflated before the sound 22 is removed from the bladder 26 and theurinary tract 24.

The apparatus 20 shown in FIGS. 1 and 2 includes a mast 144, a guide arm156 and a capture cup 162 which are also used while the sound 22 islocated in the urinary tract 24 and bladder 26. The terms “distal” and“proximal” are used in reference to the same relative positionspreviously described relative to the proximal front and rear handles 48and 50, even though the mast 144, the guide arm 156 and the capture cup162 are located on the exterior of the patient during use.

In the apparatus 20, shown in FIGS. 1 and 2, a closed mast receiver 140extends upward (as shown) from the front handle 48 and defines a pocket142 into which the mast 144 is inserted. A conventional cam latch lever146 is attached to the mast receiver 140 and is movable between anunlocked and locked positions. The cam latch lever 146 includes a cam148 that pushes the mast 144 against the mast receiver 140 when the camlatch lever 146 is in the locked position (shown in FIGS. 1 and 2).Locking the mast 144 into position within the receiver 140 holds themast 144 within the closed mast receiver 140 and also limits oreliminates any movement or play that might otherwise occur between themast 144 and the receiver 140.

An open mast receiver 150 is formed on a proximal end 152 of the guidearm 154. The open mast receiver 150 defines an opening 156 which issized to receive the mast 144 at a location vertically spaced from thelocation where the mast 144 is received in the closed mast receiver 140.A cam latch lever 158, similar to the cam latch lever 146, is attachedto the open mast receiver 150. The cam latch lever 158 is movablebetween an unlocked position (FIG. 18) and a locked position (FIGS. 1, 2and 19-22). The cam latch lever 158 locks the mast 144 in positionwithin the open receiver 150 when the cam latch lever 158 is in thelocked position. The cam latch lever 158 has a cam 160 (FIG. 2) thatpresses against the mast 144 when the cam latch lever 158 is in thelocked position, thus preventing the mast 144 from moving within theopening 156. Locking the mast 144 into position within the open receiver150 holds the guide arm 154 in a rigid position relative to the mast 144and also eliminates any movement or play that might otherwise occurbetween the mast 144 and the guide arm 154.

The mast 144 and the guide arm 154 position the capture cup 162coaxially with the expected travel path 46 of the cutting tip 40 (FIGS.18 and 19). The capture cup 162 is removably connected at a distal end164 of the guide arm 154, as described in more detail below, and is usedto safely accept, remove and retain the cutting tip 40 after it has beenused to create the surgical pathway. After the capture cup 162 hasaccepted the cutting tip 40, the capture cup 162 is manipulated todisconnect the cutting tip 40 from the advancement device 34 and releasethe capture cup 162 from the guide arm 154. The cutting tip 40 is safelyretained within the capture cup 162 to prevent inadvertent contact withthe cutting tip 40. Retaining the cutting tip 40 within the capture cup162 allows both components to be safely handled by the surgicalpersonnel without risk of encountering the cutting tip 40. Both thecapture cup 162 and the retained cutting tip 40 are disposed of as asingle device as medical waste.

An annular housing 166 is formed on the distal end 164 of the guide arm154, as shown in FIGS. 14 and 15. The annular housing 166 defines acylindrical cavity 168 which receives a funnel housing 170. The funnelhousing 170 defines an inverted funnel shape 172. The inverted funnelshape 172 has a relatively large diameter opening 174 at the bottom (asshown) of the funnel housing 170 and transversely and upwardlyconstricts to a relatively small diameter opening 176 at the top (asshown) of the funnel housing 170. An annular support lip 178 extendsradially inward from the bottom (as shown) of the annular housing 166.The support lip 178 holds the funnel housing 170 in position at thebottom of the cylindrical cavity 168 defined within the annular housing166.

The capture cup 162 releasably attaches to the top (as shown) of theannular housing 166 and sits atop the funnel housing 170 when attachedto the annular housing 166. The inverted funnel shape 172 is preferablymade from or lined with metal or hard ceramic material to prevent thecutting tip from penetrating the funnel shape 172. The funnel shape 172directs the cutting tip 40 into a cylindrical cavity 180 of the capturecup 162 (FIG. 14), after the cutting tip has created the surgicalpathway. The capture cup 162 includes a capture housing body 182 fromwhich the cylindrical cavity 180 opens downward (as shown) above thesmall diameter opening 176 of the inverted funnel shape 172. The capturehousing body 182 is preferably constructed from translucent ortransparent plastic material so that the surgeon can observe the cuttingtip 40 entering the cavity 180. The cylindrical cavity 180 has adiameter approximately equal to the diameter of the small diameteropening 176 of the inverted funnel shape 172. A relatively pliableelastomeric or polymeric sleeve 184, which is also preferablyconstructed of translucent or transparent plastic, is attached to theinside of the cylindrical cavity 180.

Bayonet fingers 186 (one of which shown in FIG. 15) extend radiallyoutward from opposing sides of an annular base 188 of the capturehousing body 182 and fit within spiral slots 190 formed in the annularhousing 166. The spiral slots 190 extend from open ends 192 which eachextend in a downward about 90 degrees in a clockwise spiral manner (asviewed from the top of the annular housing 166) around a circumferenceof the annular housing 166. The spiral slots 190 terminate at ends 194which are slightly closer to the bottom (as shown) of the annularhousing 166 than are the open ends 192 of the spiral slots 190.

The capture cup 162 is connected to the annular housing 166 by firstinserting the funnel housing 170 into the cylindrical cavity 168 withthe large diameter opening 174 of the inverted funnel shape 172 facingdownward, as shown in FIG. 15. The bayonet fingers 186 of the capturecup 162 are then aligned with and inserted into the open ends 192 of thespiral slots 190. The capture cup 162 is then rotated clockwise (asviewed from above the capture cup 162) until the bayonet fingers 186reach the ends 194 of the spiral slots 190. With the capture cup 162connected to the annular housing 166, the cylindrical cavity 180 of thecapture cup 162 is adjacent to and coaxially aligned with the smalldiameter opening 176 of the inverted funnel shape 172.

The capture cup 162 is aligned with the intended path 46 of the cuttingtip 40 when it is advanced from the distal end 28 of the sound 22.Because the advancement coil 35 is somewhat flexible in the lateralsense, the cutting tip 40 may deviate slightly from the path 46 as thecutting tip 40 is advanced. Under those conditions, the cutting tip 40will nevertheless encounter the large diameter opening 174 of theinverted funnel shape 172 when the surgical pathway is completed. Theinverted funnel shape 172 directs the cutting tip into the smalldiameter opening 176 and into the cylindrical cavity 180, despite thepossibility of a slight lateral deviation of the cutting tip 140 fromthe desired path 46 (FIGS. 21 and 22) as the surgical pathway iscreated.

The elastomeric or polymeric sleeve 184 receives or “captures” thecutting tip 40 after the cutting tip 40 enters the cavity 180. The blade41 of the cutting tip 40 cuts into the sleeve 184, as the cutting tip 40enters the cavity 180. The blade 41 of the cutting tip 40 is wider thanan inside diameter of the sleeve 184, causing the blade 41 to cut intothe sleeve 184. The elastomeric or polymeric characteristics of thesleeve 184 create friction against the blade 41 to hold the cutting tip40 in place within the cavity 180. In this manner, the cutting tip 40 isfirmly lodged within cavity 180 of the capture cup 162.

To disconnect the cutting tip 40 from the advancement device 34 aftercutting the surgical pathway and the cutting tip 40 has been receivedand held within the cavity 180 of the capture cup 162, as shown in FIG.14, the bayonet-style connections of both the capture cup 162 to theannular housing 66 and the cutting tip 40 to the advancement coil 34 aresimultaneously released by rotating the capture cup 162 in acounter-clockwise direction (as viewed from the top of the capture cup162). The cutting tip 40 rotates with the capture cup 162 due to theretention of the cutting tip 40 in the cavity 180. The cutting tipconnector 88 (FIG. 8) rotates in conjunction with the cutting tip 40 anddisconnects from the advancement device connector 90 (FIG. 8). Theadvancement device 34 is prevented from rotating by virtue of thenon-rotatable connection between the advancement device 34 and the rearhandle 50 and between the rear handle 50 and the tubular body 52 (FIGS.3 and 4). After the capture cup 162 has been disconnected from theannular housing 166 of the guide arm 154, the capture cup 162 along withthe cutting tip 40 are discarded.

Since the spiral slot 98 of the advancement device connector 90 (FIGS. 7and 8) and the spiral slots 190 of the annular housing 166 are similarlyshaped, over-rotating the capture cup 162 will not damage any of thecomponents, which might be the case if L-shaped slots were employedrather than spiral slots. Additionally, the longitudinal distancesbetween the beginning and end of the slots 98 is greater than thelongitudinal distances between the beginning and end of the slots 190resulting in as slight longitudinal force on the cutting tip when thecutting tip connector 88 is disconnected from the advancement deviceconnector 90. This slight longitudinal force causes the capture cup 162jump slightly upward upon disconnection and create a tactile indicationthat the cutting tip connector 88 has been disconnected.

An alternative embodiment of a capture cup 196 and a guide arm 198 areshown in FIG. 16A. The capture cup 196 includes a funnel housing 170A, acylindrical cavity 180A lined with an elastomeric or polymeric sleeve184A and an inverted funnel shape 172A aligned with the cylindricalcavity 180A, all of which are integral with the capture cup 196 andsimilar in shape and function to comparable elements in the capture cup162 (FIGS. 14 and 15). An annular recess 200 is defined on an exteriorof the capture cup 196. A pair of forks 202 extend distally from thedistal end of the guide arm 198 and define a semicircular-shaped opening204, as compared to the annular housing 166 of the capture cup 162(FIGS. 14 and 15). A gap 205 separates the distal ends of the forks 202.

The capture cup 196 connects to the guide arm 198 by insertion of thecapture cup 196 through the gap 205 into the semicircular-shaped opening204, with the forks 202 positioned tangentially within the annularrecess 200. The forks 202 are moderately and resiliently flexible in alateral sense and are normally separated by a diameter which is slightlyless than the inner diameter of the annular recess 200. The distal endsof the forks 202 are separated at the gap 205 when the capture cup 196is inserted between them. The forks 202 resiliently return almost totheir normal position while fitting within the annular recess 200 tofirmly hold the capture cup 196 with respect to the guide arm 198.

Once the cutting tip 40 is captured within the cavity 180A, as a resultof the blade 41 of the cutting tip 40 cutting into the elastomeric orpolymeric sleeve 184A, the capture cup 196 is rotated while the forks202 to remain in the annular recess 200. The rotation of the capture cup196 disconnects the bayonet style connection of the cutting tipconnector 88 relative to the advancement device connector 90 (FIG. 8),leaving the cutting tip within the capture cup 196. The capture cup 196is disconnected from the distal end of the guide arm 198 by separatingthe forks 202 and withdrawing the capture cup 196 from between the forks202. Thereafter the capture cup 196 and the retained cutting tip 40 canbe handled and disposed of without risk of injuring medical personnel.

One of the advantages of the fork-shaped connection arrangement betweenthe capture cup 196 and the distal end of the guide arm 198, is that thespace between the forks 202 allows additional medical equipment to beattached to the connector of the advancement device 34 without firstdisconnecting the mast 144 and/or guide arm 156, as is required in theembodiment shown in FIGS. 14 and 15. Connecting equipment to theadvancement coil 34 after removing the cutting tip 40 without firstremoving the mast 144 and the guide arm 198 presents less risk ofinadvertently losing the advancement device 34 within the surgicalpathway 29 before the additional equipment is connected.

Another embodiment 220 of a capture cup which allows equipment to beconnected to the advancement device 34 before disconnecting the guidearm and mast is shown in FIG. 16B. The capture cup 220 is similar to theintegral capture cup 196 (FIG. 16A), in that it integrally includes afunnel housing, a cylindrical cavity lined with an elastomeric orpolymeric sleeve, and an inverted funnel shape aligned with thecylindrical cavity (none of which are shown but all of which aregenerally similar to the comparable elements shown in the capture cup200, FIG. 16A). The capture cup 220 is used with an annular housing 222on the distal end of a guide arm 226. The annular housing 222 is similarto the annular housing 166 (FIG. 15), except that an opening 228 isformed in the circumference of the annular housing 222 on the oppositeside from the guide arm 226. The opening 228 allows the guide arm 226 tobe removed after the equipment has been attached to the advancementdevice 34.

The exterior surface of the capture cup 220 includes fingers 230 atdiametrically opposite exterior positions. The fingers 230 are locatedto fit within spiral slots 232 formed in the annular housing 222. Thespiral slots 232 are similar to the spiral slots 190 formed in theannular housing 166 (FIG. 15). Inserting the fingers 230 into the spiralslots 232 and twisting the capture cup 220 firmly attaches the capturecup 220 to the annular housing 222.

As an alternative to its use when retained to the guide arm, asdescribed above, the embodiments of the capture cup previously describedcan be used independently to capture and retain the cutting tip, and torelease the cutting tip from its connection to the advancement device.Such uses might not involve the use of the mast and the alignment arm ofthe cystostomy apparatus 20, but would involve the use of the sound 22.

After the cutting tip 40 is captured in the capture cup 230, the capturecup 222 is rotated to withdraw the fingers 230 from the spiral slots232. This same rotational movement disconnects the cutting tip 40 fromthe distal end of the advancement coil 35. The capture cup 222 and thecutting tip 40 which is retained within it are thereafter removed fromthe guide arm 226. Additional equipment is attached to the advancementdevice connector 90. The opening 228 in the circumference of the annularhousing 222 allows the guide arm to be removed after the additionalequipment has been attached to the advancement coil 35.

Indicia 206 are formed along the length of the mast 144. The indicia 206indicate distance between the bottom of the annular housing 166 and thetip of the distal end 28 of the sound 22. Because the tube 32 is rigid,and because the mast 144 is rigidly connected to the front handle 48 atthe mast receiver 140, and because the guide arm 154 is rigidlyconnected to the mast 144 at the mast receiver 150, this rigid geometryallows the indicia 206 to reliably measure the distance between the tipof the distal end 28 of the sound and the bottom of the annular housing166. The surgeon notes the distance between the bottom of the annularhousing 166 and the distal end 28 of the sound 22 from the indicia 206.It is this distance that the cutting tip 40 will have to be advanced tocreate the surgical pathway.

The mast receiver 140 orients the mast 144 parallel to the straightportion 47 of the rigid tube 32 at the distal end 28 of the sound 22.Because of this parallel relationship, and because the projected path 46of the cutting tip 40 is aligned with the straight portion 47 of therigid tube 32, differences in the length of the surgical pathway areaccurately indicated by the indicia 206. Furthermore, the capture cup162 remains concentrically positioned relative to the path 46 despiterepositioning the guide arm 154 along the mast 144.

An exemplary sequence of operations to perform a suprapubic cystotomywith the cystotomy apparatus 20 (FIGS. 1-16) is described below withreference to FIGS. 17-22.

The apparatus 20 is initially prepared for the cystotomy procedure bydisconnecting the mast 144 from the front handle 48, and sliding theindicator slide 66 to a proximal position abutting the front handle 48.The mast 144, guide arm 154 and capture cup 162 are removed from thefront handle 48 prior to inserting the sound 22 through the urinarytract 24 to prevent the mast, guide arm and capture cup from diminishingthe tactile feel available to the surgeon when inserting the sound 22through the urinary tract 24.

The sound 22 is inserted through the urinary tract 24 and is positionedwith the distal end 28 of the sound 22 facing toward the location on theexternal abdomen 30 from which the surgeon desires the surgical pathwayto emerge, as shown in FIG. 17. The mast 144, the guide arm 54 and thecapture cup 162 are then reconnected to the front handle 48. The mast144 is inserted into the closed mast receiver 140 of the front handle 48while the cam latch lever 146 is in the unlocked position. The mast 144is then locked into position by moving the cam latch lever 146 into thelocked position, as previously described.

The distal end 28 of the sound 22 is then pressed against the bladder 26to establish a slight “tenting” position 210 of the external abdomen 30,as shown in FIG. 18. The tenting 210 is preferably at a location on theabdomen 30 about one or two finger widths above a pubic bone 208 of thepatient.

The open mast receiver 150 is then unlocked by moving the latch lever158 into the unlocked position, which allows the guide arm 154 to belowered along the mast 144. Lowering the guide arm 154 in this mannerplaces the capture cup 162 immediately above the tenting position 210,with the annular housing 166 resting on the external abdomen 30, asshown in FIG. 19. The cam latch lever 158 is then moved to the lockedposition locking the guide arm 154 into position relative to the mast144. The mast 144 and the guide arm 154 position the capture cup 162coaxial to the path 46 along which the cutting tip 40 is intended to beadvanced.

With the guide arm 154 and the capture cup 162 in the position shown inFIG. 19, the surgeon then observes the separation distance between thetip of the distal end 28 of the sound 22 and the bottom of the annularhousing 166, by use of the indicia 206. This distance represents theamount of advancement of the cutting tip 40 necessary to create thesurgical pathway 29 (FIGS. 21 and 22).

The inflatable balloon 136 is then inflated to prevent the distal end 28of the sound 22 from extending into the surgical pathway when thecutting tip 40 is advanced, as shown in FIG. 20. The indicator slide 66is then moved along the hollow rigid tube 32 to abut against theexternal opening 64 of the urinary tract 24. The surgeon uses theindicia 62 along the hollow tube 32 to mark the desired position of thesound 22 within the urinary tract 24 and to also recognize unintendeddistal or proximal movement of the apparatus 20.

The cutting tip 40 is then advanced from the distal end 28 of the sound22, as shown in FIG. 21, by moving the rear handle 50 (FIGS. 1 and 2)distally towards the front handle 48. The cutting tip 40 advances alongthe path 46 and cuts through the bladder 26 and the intervening tissueto the external abdomen 30, thereby creating the surgical pathway 29which extends from inside the bladder 26 to outside of the patient atthe external abdomen 30.

Advancement of the cutting tip 40 continues until the cutting tip 40enters the cylindrical cavity 180 (FIGS. 14 and 15) of the capture cup162 and becomes lodged within the sleeve 184 (FIGS. 14 and 15), as shownin FIG. 22. The surgeon knows how far the cutting tip 40 must advance toenter the capture cup 162 by reference to the indicia 206 on the mast144. The extent of advancement of the cutting tip 40 is determined byreference to the indicia 68 (FIG. 1) on the tubular body 52 distal tothe rear handle 50. The surgeon is assured that the cutting tip 40 hasentered the capture cup 162 by visually observing the presence of thecutting tip 40 through the transparent or translucent capture cup 162.The cutting tip 40 should be observable within the capture cup 162 whenthe rear handle 50 moves slightly past the indicia 68 on the tubularbody 52 corresponding to the distance indicated by the indicia 206 onthe mast 144 between the tip of the distal end 28 of the sound 22 andthe annular housing 166.

After the cutting tip 40 has been successfully captured within thecapture cup 162, the capture cup 162 is rotated counter-clockwise (asviewed from above the capture cup 162) at least 90 degrees. Thecounter-clockwise rotation of the capture cup 162 simultaneouslydisconnects the cutting tip 40 from the advancement coil 35 and thecapture cup 162 from the annular housing 166. In the embodiment whichutilizes the interdigitated connections 110 and 112 (FIGS. 9 and 10),the lock wire 128 is retracted prior to separating the capture cup 162(or 196) from the annular housing 166 at the distal end of the guide arm154 (or from the semicircular opening 204 at the distal end of the guidearm 198). The capture cup with the retained cutting tip may thereafterbe handled safely and disposed of as medical waste.

After the surgical pathway 29 has been created as shown in FIG. 22, itmust be held open. Otherwise the pathway will collapse and will becomeimpossible or very difficult to insert any equipment through thesurgical pathway. To avoid collapse, a material object must always bepresent within the surgical pathway 29, thereby maintaining the surgicalpathway 29.

The apparatus 20 is used to assist with the insertion of a cannula 400(FIG. 33) within the surgical pathway 210, by which to access thebladder 26 with additional medical instruments (e.g., 414, FIG. 41) fromoutside of the patient to perform medical procedures inside the bladder26. The apparatus 20 may also be used to assist with the insertion of acatheter (not shown) by which to drain urine from the bladder 26. Theprocedure and details of inserting the catheter through the surgicalpathway into the bladder are described more completely in thepreviously-identified U.S. application Ser. No. 12/238,941. Theremaining portion of the description contained herein will focusprincipally on inserting the cannula 400, although some of the followingdiscussion is also applicable to inserting the catheter.

Prior to inserting the cannula 400 (FIG. 27), the surgical pathway 29must be widened enough to receive the cannula 400. The cannula 400 has atransverse width that is significantly greater than the width of thecutting tip 40. Consequently, the cannula 400 will not fit within thesurgical pathway 29 without first widening it.

A dilator 350, shown in FIGS. 23 and 25, is used to widen the surgicalpathway 29. The relative terms “proximal” and “distal” are used hereinin relation to the cannula 400, the dilator 350 and the other equipmentused with the cannula 400 and dilator, in relation to the medicalpractitioner who inserts the cannula 400, dilator 350 and otherequipment used with both into the surgical pathway 29. Accordingly, theportions of the cannula 400 and dilator 350 which are the most internalwithin the surgical pathway or the patient, and are therefore morefarther removed from the surgeon, are referred to as “distal.” Theportions of the cannula 400, dilator 350 and the equipment used withboth which are closest to the surgeon relative to the surgical pathwayare referred to as “proximal.” Additionally, the dilator 350, cannula400 and obturator 450 are shown in exaggerated scale relative to theapparatus 20 and bladder 26 and urinary tract 24 in FIGS. 26-32, 36-38and 40-41 for clarity of understanding.

The dilator 350 has a main body portion 352 which is generallycylindrically shaped. The body portion 352 remains outside of theexterior abdomen 30. The dilator 350 also includes a pair of spacedapart arms 354 which extend from the body portion 352 and are insertedinto the surgical pathway 29. The body portion 352 includes an upperring portion 356 from which there extend distally a pair ofdiametrically opposite and longitudinally extending arm receivers 358and a pair of diametrically opposite and longitudinally extendingsidewalls 360 located between the arm receivers 358. The sidewalls 360and the arm receivers 358 are each separated circumferentially by asmall gap 362. Four small gaps 362 are therefore located around the bodyportion 352.

The arm receivers 358 and the sidewalls 360 are integrally connected attheir proximal ends with the annular ring portion 356. The annular ringportion 356 is located at proximal end of the body portion 352. The ringportion 356 includes an insertion slot 359 and an annular retentiongroove 361 formed adjacent to its proximal end. The insertion slot 359and retention groove 361 are adapted to receive complementary-shapedconnection fingers (not shown) of a stylet 390 (FIG. 23) and of acannula 400 (FIG. 33) to connect those components to the dilator 350during different stages of use discussed below. The insertion slots 359and retention groove 361 interact with a complementary-shaped connectionfinger (not shown) of the stylet and the cannula to create abayonet-style connection. Finger grips 363 protrude outwardly from thedistal ends of each arm receiver 358. The finger grips 363 are usefulfor maintaining the dilator 350 in a generally stabilized position whenthe surgeon applies force with other equipment used with the dilator, asdiscussed below.

One of the arms 354 extends distally forward and generally parallel fromeach of the two arm receivers 358, as is shown in FIGS. 23, 24A and 25.The arm receivers 358 each contain a cavity 365 at their distal endsinto which a proximal end of one of the arms 354 is inserted. Theproximal end of each arm 354 is held in place in the cavity 365 byadhesive, after the other components associated with each arm 354 havebeen assembled.

The arms 354 have a generally crescent-moon shaped cross section asshown in FIG. 24B. A center cavity 364 extends along the full length ofeach arm 354. A window 366 (FIG. 23) extends from the outside surface ofthe distal end of each arm 354 into the center cavity 364.

A tab 368 extends longitudinally within and along the full length of thecenter cavity 364 of each arm 354. Wings 372 are located at the proximalends of each longitudinal tab 368, as shown in FIGS. 24A and 24C. Thewings 372 are preferably integrally formed with the longitudinal tabs368, such as by molding them from plastic material as the tabs 368 aremade. The wings 372 move proximally and distally within longitudinaltracks 374 formed in the exterior surfaces of the arm receivers 358.

Each tab 368 is inserted in the center cavity 364, and its distal end isconnected to the distal end of the center cavity 354 by adhesive. Thewing 372 is inserted in the longitudinal tracks 374 while the proximalend of the arm 354 is inserted into the cavity 365. Adhesive is appliedto the exterior of the proximal end of the arm 354 to hold it in itsinserted position in the cavity 365. In this manner each arm 354 isassembled to its arm receiver 358.

Stress risers 376 are located on the longitudinal tabs 368, near thedistal ends 370. The stress risers 376 cause portions 377 of thelongitudinal tabs 368 to deflect out through the windows 366 when thetabs 368 and the wings 372 are moved toward the distal end of the tracks374, as shown in FIGS. 23 and 24C. Sliding the wings 372 toward theproximal end of the tracks 374 cause the portions 377 of thelongitudinal tabs 368 to retract into the windows 366 as shown in FIG.26.

Parallel side cavities 378 are formed within the arms 354 on oppositesides of the center cavity 364, as shown in FIG. 24B. The side cavities378 extend the entire length of the arms 354. The parallel side cavities378 hold a wire loop 380 at the distal ends of each arm 354. The wireloop 380 is formed by bending the center of a relatively long wire 382into a right angle U-shape, as shown in FIG. 24D. The two relativelylengthy end portions 383 of the wire 382 extend from the loop 380 in aparallel relationship with one another. The end portions 383 areinserted into the side cavities 378 of each arm 354 and are held thereby an adhesive. The end portions 383 of each wire 382 extend the entirelength of each arm 354 within the side cavities 378. The end portions383 of each wire 382 strengthen the arms 354 when inserted in the sidecavities 378. The U-shaped portion of each wire 382 forms the wire loop380 which protrudes inwardly from the distal end of each arm 354 towardthe other arm 354, as shown in FIG. 23.

Indicia 384 are formed along the length of at least one of the arms 354,as shown in FIG. 25. The indicia 384 indicate a distance from a proximalend of the windows 366. The surgeon correlates the distance indicated bythe indicia 384 with the thickness of the abdomen indicated by theindicia 206 of the mast 144 to determine when the dilator 350 isinserted within the surgical pathway 29 deeply enough to position thewindows 366 within the bladder 26 to allow the portions 377 of thelongitudinal tabs 368 to protrude from the windows 366 and anchor thedilator 350 in the bladder 26.

A disc-shaped flexible retention ring 386 is slidably positioned overthe arms 354. A hollow center 387 through the retention ring 386 permitsthe arms 354 to pass through the retention ring 386. The retention ring386 is movable along the arms 354 to abut against the external abdomen30 when the dilator 350 is at the desired depth in the surgical pathway.Contacting the retention ring 386 against the external abdomen preventsthe dilator 350 from moving into the bladder 26 from the desiredposition, while the expanded portions 377 of the longitudinal tabs 368prevent the dilator 350 from moving out of the bladder 26. In thismanner, the dilator retained or anchored on opposite sides of theabdominal tissue which separates the bladder 26 from the externalabdomen 30.

Slight flexibility in the annular ring portion 356 of the body 352allows the distal ends of the arm receivers 358 to be squeezed slightlytoward one another, as shown in FIG. 25, allowing the distal ends of thearms 354 to move closely adjacent to one another. The wire loops 380 areslightly offset from one another in a longitudinal direction so thatthey overlap to jointly form an enclosure 385 (FIG. 25) when the arms354 are our moved toward each other. A distal end of a stylet 390 (FIG.23) is inserted through the enclosure 385 formed by the overlapping wireloops 380, as shown in FIG. 25. Holding the distal ends of the arms 354together with a stylet 390 allows the dilator 350 to be inserted intothe surgical pathway 29.

The stylet 390 includes a distal end connector 392 and a knob 394separated by a long narrow shaft 396. The distal end connector 392 onthe shaft 396 is substantially similar in shape to the bayonet stylecutting tip connector 88 (FIGS. 7 and 8) of the cutting tip 40 (FIGS. 7and 8), or to the interdigitated cutting tip connector 110 (FIGS. 9 and10). For purposes of the following description, the distal end connector372 is described as the bayonet connector, although the interdigitatedconnector could also be used as an alternative. The bayonet connector392 is intended to be connected to the advancement device connector 90(FIGS. 7 and 8) of the advancement coil 35 (FIG. 7). The shaft 396 isrelatively rigid so that it may transfer rotational force from the knob394 to the bayonet connector 392.

The stylet 390 is attached to the dilator 350 as shown in FIG. 25 byinserting the shaft 396 through an annular opening 398 in the ringportion 356 of the dilator body 352. Continued insertion of the stylet390 into the dilator 350 while pressing the arm receivers 358 inwardpositions the shaft 396 between the spaced apart arms 354 and throughthe enclosing wire loops 380 at the distal ends of the arms 354, thussecuring the distal ends of the arms 354 against the shaft 396.

The bayonet connector 392 and a short distal part of the shaft 396extend distally beyond the overlapped wire loops 380. The wire loops 380retain the distal ends of the arms 354 close to the shaft 396.Maintaining the distal ends of the arms 354 close to the shaft 396facilitates insertion of the dilator 350 into the surgical pathway 29 byminimizing the cross sectional area of the dilator 350 and by preventingthe distal ends of the arms 354 from projecting into the tissuesurrounding the surgical pathway.

The interior of the knob 394 is hollow and is adapted to connect to theproximal ring portion 356 of the main body 352 of the dilator 350 (FIG.25). The interior of the knob 394 includes two diametrically oppositeand radially inward projecting connection fingers (not shown) which areadapted to be inserted within the insertion slots 359 and to be rotatedwithin the retention groove 361 of the ring portion 356 (FIG. 23) in abayonet-style connection manner to hold the stylet 390 within thedilator 350.

The bayonet connector 392 is connected to the advancement deviceconnector 90, as shown in FIG. 26. The bayonet connector 392 connects tothe advancement device connector 90 in the same manner as the cuttingtip connector 88 connects to the advancement device connector 90 (FIGS.7 and 8). The opening 228 in the annular housing 222 (FIG. 16B), or thegap 205 between the forks 202 (FIG. 16A), permits the mast 144 and guidearm 154 (or 198) to be removed and set aside after the connected dilator350 and stylet 390 are attached to the advancement coil 35. Otherwisethe mast 144 and the guide arm 154 (FIG. 1) must be removed and setaside before the connected-together stylet 390 and dilator 350 areconnected to the advancement device connector 90. The retention ring 386is moved far enough up the arms 354 in the proximal direction to ensurethat the retention ring 386 does not interfere with the insertion of thedilator 350 to a desired depth within the surgical pathway 29.

After the connectors 392 and 90 are connected, the surgeon moves therear handle 50 (FIGS. 1 and 2) rearwardly or proximally away from thefront handle 48 to retract the advancement device 34. The retraction ofthe advancement device 34 moves the connected stylet 390 and dilator 350into the surgical pathway 29, as shown in FIG. 27.

While or after retracting the advancement device 34, the distal end 28of the sound 22 is moved away from the bladder 26, as shown in FIG. 28.The inflatable balloon 136 (FIGS. 26 and 27) may also be collapsed atthis time.

The combined retraction of the advancement device 34 and the sound 22moves the distal ends of the connected dilator 350 and stylet 390sufficiently into the bladder to position the windows 366 (FIG. 25) inthe arms 354 in the bladder 26, as shown in FIG. 29. The indicia 384(FIG. 25) on the arms 354 indicate the distance within the surgical path29 that the dilator 350 has been inserted. The distance of insertion ofthe dilator 350 should be greater than the thickness of the tissuebetween the bladder 26 and the external abdomen 30, as earlierdetermined by reference to the indicia 206 on the mast 144, in order tolocate the windows 366 within the bladder 26. After the dilator 350 hasbeen inserted into the surgical pathway 29 to the desired depth, theretention ring 386 is moved down the arms 354 to abut against theexternal abdoment 30 and anchor the dilator 350 against further distalmovement into the bladder 26.

After the dilator 350 has been inserted into the surgical pathway 29 asshown in FIG. 29, the surgeon presses downward on the wings 372 toexpand the longitudinal tabs 368 from the windows 366 (FIG. 25). Theprotrusion of the tabs 368 from the windows 366 contacts the inner wallof the bladder 26 adjacent to the surgical pathway 29 and therebyanchors the dilator 350 in the surgical pathway. Anchoring the dilator350 in this manner prevents it from unintended withdrawal from thesurgical pathway.

After the dilator 350 has been anchored, the knob 394 of the stylet 390is rotated sufficiently to disconnect the bayonet connector 392 from theadvancement device connector 90 thereby disconnecting the stylet 390from the advancement coil 35 (FIG. 7), as shown in FIG. 29. After thestylet 390 has been disconnected from the advancement coil 35 after thedilator 350 has been anchored in the bladder, the sound 22 is removedfrom the urinary tract 24, as shown in FIG. 30.

The stylet 390 is then removed from the dilator 350 by rotating the knob394 relative to the ring portion 356 of the main body 352, therebydisconnecting the bayonet-style connection formed by the internalfingers within the knob 394 (not shown) and the insertion slot 359 andretention groove 361 (FIG. 23). The shaft 396 is then withdrawn from theannular opening 398 in the annular ring portion 356 of the main body352, as shown in FIG. 31. Removing the stylet 390 in this manner leavesonly the dilator 350 in the surgical pathway 29 (FIG. 32).

With the dilator 350 successfully inserted and anchored in the surgicalpathway 29, a cannula 400, shown in FIG. 33 and an obturator 450, shownin FIG. 34, which are connected together as shown in FIG. 35, are thenjointly inserted while connected together into the dilator 350. Theinsertion of the connected together cannula 400 and obturator 450 intothe dilator 350 expands the surgical pathway 29 (FIGS. 36-37).

The cannula 400, shown in FIG. 33, includes a hollow tube portion 402and a hollow body portion 404. A center passageway 405 extendscompletely along the length of the cannula 400. A distal part 406 of thebody portion 404 is hollow at the exterior of the tube portion 402 andis adapted to connect to the proximal ring portion 356 of the main body352 of the dilator 350 (FIGS. 23 and 39). The interior of the distalpart 406 includes two diametrically opposite and radially inwardprojecting connection fingers (not shown) which are adapted to beinserted within the insertion slots 359 and to be rotated within theretention groove 361 of the ring portion 356 (FIG. 23) in abayonet-style connection manner to hold the cannula 400 within thedilator 350.

The body portion 404 also includes a fluid port 408 which communicateswith the center passageway 405 of the tube portion 402. The fluid port408 is used to flush fluid into the bladder 26 during a medicalprocedure, if desired by the surgeon, when the cannula 400 is connectedto the dilator 350 and located in the surgical pathway. The body portion404 also includes a opening 410 by which to access the interiorpassageway 405 extending through the dilator 400. A conventional domeseal 412 extends across the opening 410 to seal the opening 410 when nomedical instrument is inserted through the opening 410. The dome seal412 includes at least one slit which allows the dome seal 412 toseparate sufficiently to accept a medical instrument 414 insertedtherethrough into the cannula 400 and bladder 26 (FIG. 41). The domeseal 412 also collapses around the inserted medical instrument 414 toretard the flow of fluid from the bladder through the tube portion 402.A conventional pressure seal (not shown) is also included within thetube portion 402 of the cannula 400 to seal the interior passageway 405against a medical instrument is inserted through the cannula 400 (FIG.41).

The obturator 450, shown in FIG. 34, has a cylindrical shaft 452 whichextends distally to a tapered and rounded distal end 454. A push cap 456extends from the proximal end of the cylindrical shaft 452. Theobturator 450 is used to assist the insertion of the cannula 400 (FIG.33) into the dilator 350 (FIG. 23).

The tapered distal end 454 and the shaft 452 of the obturator 450 isinserted through the dome seal 412 and the cylindrical opening 410 andinto the interior passageway 405 of the cannula 400. The shaft 452 ispushed into the passageway 405 until the push cap 456 abuts the bodyportion 404 of the cannula 400, and the tapered distal end 454 extendsdistally beyond the distal end of the tube portion 404 of the cannula400, as shown in FIG. 35.

The combined cannula 400 and obturator 450 are then inserted into thedilator 350 by inserting the tapered distal end 454 into the annularopening 398 in the ring portion 356 of the dilator body 352, as shown inFIG. 36. The surgeon pushes on the push cap 456 while holding thedilator 350 steady at the finger support groups 363 (FIG. 23) to forcethe cannula 400 and obturator 450 into the dilator 350. As the combinedcannula 400 and obturator 450 are inserted into the dilator 350, thearms 354 are pushed outward by a camming effect from the tapered point454 against the arms 354. The arms move from the inwardly bowed inorientation (FIG. 25) to an outward parallel orientation (FIGS. 23 and37). The tapered distal end 454 gently forces the arms 354 of thedilator 350 apart from one another while simultaneously enlarging thetransverse width of the surgical pathway 29. The degree of taper andcurvature of the distal end 454 causes the tissue surrounding thesurgical pathway to expand elastically. The wire loops 380 of thedilator 350 deflect laterally to the outside of the cannula 400 as theconnected cannula 400 and obturator 450 move between the distal ends ofthe arms 354.

After the connected cannula 400 and obturator 450 are fully insertedinto the dilator 350, as shown in FIG. 37, the cannula 400 and dilator350 are attached to each other by engaging inside bayonet-styleconnection at the distal end of the distal part 406 of the body portion404 (not shown), with the insertion slot 359 and retention groove 361 ofthe ring portion 356 of the dilator 350 (FIG. 23). In this manner, thecannula 400 is firmly connected to the dilator 350, and the dilator 350is firmly anchored in the bladder by the protruding deflection portions377 of the longitudinal tabs 368 (FIG. 39). The obturator 450 is thenremoved from the cannula 400, as shown in FIG. 38, leaving the connecteddilator 350 and cannula 400 in the surgical pathway as shown in FIGS. 39and 40.

The cylindrical opening 410 and interior passageway 405 of the cannula400 provide access into the bladder 26 for medical instruments 414inserted through the dome seal 412, as shown in FIG. 41. The medicalinstruments are manipulated from the outside of the patient to performmedical procedures within the bladder 26.

The cannula 400 and dilator 350 remain in place for the duration of themedical procedure. To remove them after the procedure is complete, thecannula 400 is disconnected from the main body 352 of the dilator 350,by twisting and unlocking the bayonet-style internal connection betweenthe distal end of the park 406 and the slots 359 and retention grooves361 on the annular ring 356 of the body 352 of the dilator 350 (FIG.23). The cannula 400 is then withdrawn from the dilator 350 in theopposite direction from which it was inserted. The wings 372 are movedproximally in their tracks 374, causing the deflection portions 377 ofthe longitudinal tabs 368 to retract from their extended position intothe windows 366 and the center cavity 364 of the arms 354. The arms 354are free to move together, and the wire loops 380 are free to overlapeach other. The arms 354 are withdrawn from the surgical pathway 29 bypulling the dilator 350 out of the surgical pathway away from theexternal abdomen 30 using the finger support groups 363 (FIG. 23). Thesurgical pathway 29 collapses after removal of the dilator 350. Thenatural bodily healing process seals the surgical pathway with time.

In the manner described above, the cystotomy apparatus 20 is usedeffectively to create the surgical path 29, while providing the surgeonwith improved control to locate the surgical path as desired and tocreate the surgical path efficiently with minimum of trauma to thepatient. The dilator 350, which is used in connection with the stylet390 and the cystotomy apparatus 20, is effectively drawn into thesurgical pathway to maintain that pathway. The cannula 400 and theobturator 450 are readily inserted through the dilator to expand thesurgical pathway sufficiently to accept the cannula 400 without tearingthe surgical pathway and inducing additional trauma to the patient.Removal of the obturator 450 from within the cannula 400 leaves apathway for 05 through the cannula 400 which readily accepts medicalinstruments 414 to execute a desired medical procedure.

Features of the cystotomy apparatus 20, the dilator 350, the stylet 390,the cannula 400 and the obturator 450 interact in a complementary mannerwhich facilitates the effective execution of the medical procedure. Manyother advantages and improvements will be apparent upon fullyappreciating the many significant aspects of the invention describedabove.

Presently preferred embodiments of the invention have been describedwith a degree of particularity. This description is of preferredexamples of implementing the invention, and is not necessarily intendedto limit the scope of the invention. The scope of the invention isdefined by the following claims.

What is claimed:
 1. A dilator for inserting a cannula into a surgicalpathway extending between a bladder and an external abdomen, comprising:a body which is located outside of the abdomen, the body including aring portion which defines a central opening about a central axisthrough which the cannula is inserted; a plurality of arm receiversconnected to the ring portion on opposite sides of the central axis; aplurality of substantially straight and elongated arms for insertioninto the surgical pathway, each arm connected to and extending distallyfrom one arm receiver, each arm having a central passageway whichextends substantially along the length of the arm, each arm defining awindow into the central passageway facing outward from the central axisat a position adjacent to the distal end of the arm; a longitudinal tabmember positioned within the central passageway of each arm, thelongitudinal tab member extending from a distal end located at thedistal end of the arm past the window to a proximal end located in thearm receiver; a wing member attached to the proximal end of thelongitudinal tab member, the wing member movably positioned in alongitudinally extending slot formed in the arm receiver, the wingmember movable in the slot in distal and proximal directions to move theportion of the longitudinal tab member which is proximal to the windowin distal and proximal directions within the central passageway; aportion of the longitudinal tab member adjacent to the window includingstress risers adjacent to deflection portions of the longitudinal tabmember, the stress risers directing the deflection portions to protrudeoutwardly through the window upon longitudinal distal movement of thelongitudinal tab member by the wing member and to withdraw thedeflection portions into the window upon longitudinal proximal movementof the longitudinal tab member by the wing member; the centralpassageway of each arm extending substantially straight between thewindow and the proximal end of each arm; and the proximal and distalmovement of the wing member in the slot occurring in substantiallystraight alignment with the portion of the longitudinal tab memberextending in the center passageway of each arm.
 2. A dilator as definedin claim 1, further comprising: indicia formed at intervals along atleast one arm to indicate the depth of movement of the dilator into thesurgical pathway.
 3. A dilator as defined in claim 1, furthercomprising: a loop connected at each distal end of each arm on oppositesides of the central axis; each loop extending toward the central axis;the loops at the end of the arms occupying respectively differentpositions to allow the loops to overlap upon transverse inwarddeflection of each arm to the central axis.
 4. A dilator as defined inclaim 3, further comprising in combination a stylet, wherein the styletcomprises: a shaft having a longitudinal length that is greater than thelength of the arms of the dilator; a stylet connector formed on a distalend of the shaft, the stylet connector adapted to releasably connectwith a complementary connector of a device located in the surgicalpathway; and the shaft extending through the center opening along thecentral axis with the distal end of the shaft of the stylet extendingthrough the overlapped loops on the distal ends of the arms to hold thearms deflected transversely inwardly during insertion of the dilator inthe surgical pathway.
 5. A dilator in combination with the stylet asdefined in claim 4, wherein: each arm includes side cavities formed onopposite transverse sides of the central passageway; and each loop isformed by a wire curved in the form of a loop having ends extending intothe side cavities of the arm to which the loop is connected.
 6. Adilator in combination with the stylet as defined in claim 5, wherein:the ends of each wire extend substantially the entire length of eacharm.
 7. A dilator in combination with the stylet as defined in claim 4,wherein: the ring portion includes a connector surrounding the centeropening; the shaft of the stylet includes a knob at a distal end; andthe knob includes a complementary connector for connecting with theconnector on the ring portion upon insertion of the stylet through thecenter opening and the distal end of the shaft through the overlappedloops.
 8. A dilator in combination with the stylet as defined in claim7, wherein: the complementary connectors between the knob and the ringportion, and the complementary connectors between the distal end of theshaft and the device in the surgical pathway, release from one anotherby movement of the knob relative to the ring portion.
 9. A dilator incombination with a cannula as defined in claim 1, wherein: the cannulacomprises a cannula tube which defines an internal passageway forinserting and manipulating medical instruments; and further comprising:an obturator comprising an obturator shaft adapted to be removablyreceived within the internal passageway of the cannula tube, theobturator shaft having a distal end of tapered and rounded shape whichprotrudes beyond the distal end of the cannula tube; and wherein: thecenter opening of the dilator receives the cannula tube and theobturator inserted within the cannula tube, the arms of the dilatoroperatively expanding transversely to accommodate the cannula tube andthe obturator shaft as the cannula and the obturator move distally intothe center opening of the dilator, the expansion of the arms to acceptthe cannula and the obturator expanding the surgical pathway.
 10. Adilator in combination with the cannula, as defined in claim 9, wherein:the ring portion includes a connector surrounding the center opening;the cannula includes a distal body portion through which the cannulatube extends; the distal body portion of the cannula includes acomplementary connector for connecting with the connector on the ringportion upon insertion of the cannula through the center opening of thedilator.